This invention relates to a power steering apparatus for an automobile which can be easily assembled and installed and which has good heat resistance.
Recently, unitized power steering devices for automobile have been developed. These devices include an electric motor, a speed reducer, a torque sensor, and a motor controller on a circuit board, all enclosed within a single sealed housing. Such power steering devices are extremely compact and can be easily installed on the end of a steering shaft. A unitized power steering device of this type is disclosed in Japanese Published Unexamined Patent Application No. 60--234069.
However, because the electric motor and the motor controller are sealed inside the housing, it is difficult to cool them, and they can easily suffer from thermal damage.